A pronoun can replace a noun or another pronoun. You use pronouns like "he," "which," "none," and "you" to make your sentences less cumbersome and less repetitive.

Grammarians classify pronouns into several types, including the personal pronoun, the demonstrative
pronoun, the interrogative pronoun, the indefinite pronoun, the relative pronoun, the reflexive pronoun, and the intensive
pronoun.

A possessive pronoun indicates that the pronoun is acting as a marker of possession and defines who owns a particular object
or person. The possessive personal pronouns are "mine," "yours," "hers," "his," "its," "ours," and "theirs." Note that possessive personal pronouns
are very similar to possessive adjectives like "my," "her," and "their."

In each of the following sentences, the highlighted word is a possessive personal pronoun:

A demonstrative pronoun points to and identifies a noun or a pronoun. "This" and "these" refer to things that are nearby either
in space or in time, while "that" and "those" refer to things that are farther away in space or time.

The demonstrative pronouns are "this," "that," "these," and "those." "This" and "that" are used to
refer to singular nouns or noun phrases and "these" and "those" are used to refer to plural nouns and noun phrases. Note that the demonstrative pronouns are identical to demonstrative adjectives, though, obviously, you use them differently. It is also important to note that "that" can also be used
as a relative pronoun.

In the following sentences, each of the highlighted words is a demonstrative pronoun:

This must not continue.

Here "this" is used as the subject of the compound verb "must not continue."

This is puny; that is the tree I want.

In this example "this" is used as subject and refers to something close to the speaker. The demonstrative
pronoun "that" is also a subject but refers to something farther away from the speaker.

An interrogative pronoun is used to ask questions. The interrogative pronouns are "who," "whom," "which," "what" and the compounds
formed with the suffix "ever" ("whoever," "whomever," "whichever," and "whatever"). Note that either "which" or "what" can also
be used as an interrogative adjective, and that "who," "whom," or "which" can also be used as a relative pronoun.

You will find "who," "whom," and occasionally "which" used to refer to people, and "which" and "what"
used to refer to things and to animals.

"Who" acts as the subject of a verb, while "whom" acts as the object of a verb, preposition, or a verbal.

The highlighted word in each of the following sentences is an interrogative pronoun:

Which wants to see the dentist first?

"Which" is the subject of the sentence.

Who wrote the novel Rockbound?

Similarly "who" is the subject of the sentence.

Whom do you think we should invite?

In this sentence, "whom" is the object of the verb "invite."

To whom do you wish to speak?

Here the interrogative pronoun "whom " is the object of the preposition "to."

Who will meet the delegates at the train station?

In this sentence, the interrogative pronoun "who" is the subject of the compound verb "will meet".

To whom did you give the paper?

In this example the interrogative pronoun "whom" is the object of the preposition "to."

What did she say?

Here the interrogative pronoun "what" is the direct object of the verb "say."

You can use a relative pronoun is used to link one phrase or clause to another phrase or clause. The relative pronouns are "who," "whom," "that," and "which." The compounds
"whoever," "whomever," and "whichever" are also relative pronouns.

You can use the relative pronouns "who" and "whoever" to refer to the subject of a clause or sentence,
and "whom" and "whomever" to refer to the objects of a verb, a verbal or a preposition.

In each of the following sentences, the highlighted word is a relative pronoun.

You may invite whomever you like to the party.

The relative pronoun "whomever" is the direct object of the compound verb "may invite".

The candidate who wins the greatest popular vote is not always elected.

In this sentence, the relative pronoun is the subject of the verb "wins" and introduces the subordinate clause "who wins the greatest popular vote". This subordinate clause acts as an adjective modifying "candidate."

In a time of crisis, the manager asks the workers whom she believes to be the most efficient
to arrive an hour earlier than usual.

In this sentence "whom" is the direct object of the verb "believes" and introduces the subordinate
clause "whom she believes to be the most efficient". This subordinate clause modifies the noun "workers."

Whoever broke the window will have to replace it.

Here "whoever" functions as the subject of the verb "broke".

The crate which was left in the corridor has now been moved into the storage closet.

In this example "which" acts as the subject of the compound verb "was left" and introduces the subordinate
clause "which was left in the corridor." The subordinate clause acts as an adjective modifying the noun "crate."